What does the cost principle require in accounting?

A$.$ Transactions should be recorded at their market value

B$.$ Transactions should be recorded at the fair value at the time of recognition

C$.$ Transactions should be recorded at the exchange price at the time of recognition

D$.$ Transactions should only be recorded if they involve tangible assets

In the double$-$entry accounting system, which of the following is a requirement?

A$.$ Each transaction must be recorded with multiple debits and a single credit

B$.$ The total amount of debits must be less than the total credits

C$.$ Debits and credits should always be recorded separately

D$.$ Each transaction must be recorded with at least one debit and one credit, and the total amount of the debits must equal the total amount of the credits